A sample of wheat grown using high-intensity light-emitting diodes developed by WCSAR. The lights are similar to the red lights on a stereo and bathe the plants in the precise amount of simulated sunlight. (large image)

The project begins with 14 seeds of a special dwarf variety of wheat, which grows only 9 inches tall. If successful, it will end 80 days later with mature plants producing seeds of their own.

NASA Space Shuttle Endeavour, launched on Thursday, Jan. 22, is carrying the wheat seeds in a specially designed plant growth chamber created by WCSAR. The unit will be transferred to Mir to complete its growing season, then be transported back home in May aboard the Space Shuttle Discovery.

Raymond Bula, director of WCSAR at the University of Wisconsin-Madison, says the experiment is the most commercially exciting of its six space missions since 1992. Some early evidence indicates that genetic information could be transferred more efficiently in space, he says, suggesting that heartier crops and new drugs could be engineered in microgravity.

"We're looking at the ability to grow plants that have some economic meaning, rather than just growing plants as a model," says Bula. "We see potential for using plants as a biofactory in space."

Long before that happens, scientists must bolster the evidence that plants can complete a full life cycle and regenerate in space. Two previous experiments in 1995 and 1996 involving the same dwarf wheat variety, developed at Utah State University, failed to yield fully mature plants that produced seeds, he says.

But in August, a project aboard Mir with another Wisconsin connection achieved that important milestone. An experiment run by Louisiana State University scientists used Wisconsin Fast Plants, a quick-growing mustard plant developed at UW-Madison, to grow plants from seed to flower to seed in just 40 days.

The achievement with Fast Plants gives Bula greater optimism for the wheat experiment, especially with the addition of the sophisticated controls of their plant growth chamber. Called Astroculture, the growth chamber enables plants to grow under extremely precise controls for temperature, light, humidity and nutrients.

Temperature and humidity, for example, can be controlled for the duration of the experiment, he says. The lighting is provided by high-intensity light-emitting diodes - similar to the red lights on a stereo - that bathe the plants in the precise amount of simulated sunlight. And the water and nutrients are delivered through porous stainless steel tubes.

In 1995, the potato-growth experiment showed that microgravity had no negative effects on the development of potato tubers. Aside from increased amounts of protein, the space tubers differed little from their Earth-grown kin.

Bula says future experiments will ask the question differently: Rather than hinder plant growth, can microgravity actually have benefits? One theory holds that eliminating "buoyancy effects" caused by gravity allows the cells to remain in suspension. In doing so, the DNA materials could more easily interact during cell division. This increases the chances of incorporating desirable genes and enhancing the genetic engineering of new plant materials.

Some agricultural companies are intrigued by the possibility of doing space-based plant research, and WCSAR has industry partnerships with several soybean firms that are planning future projects. WCSAR has developed a much larger plant-growth chamber, about the size of a large microwave, for eventual use on the International Space Station planned for shortly after the turn of the century. Unlike the current chamber, which is about 9 inches tall, the new chamber could be suitable for growing soybeans, the second-largest cash crop in the United States.

"Some companies are interested in doing a plant project in space right now - they don't want to wait four years for an international space station," Bula says. "The potential is definitely there to create new products and get new values in agriculture."